The present invention relates generally to computer software, and more particularly, to a system and method for utilizing hash buckets for managing workload in a multiple processor computer system.
In today's computer network environment, large volumes of data are customarily shared by multiple computers. In order to improve upon the efficiency of the computer network, multiple computer processors share the workload as well. Especially in a multiple processor computer system where a network protocol such as TCP/IP is used to link all participating processors, it is desirable to have the TCP/IP workload evenly distributed across these processors.
The current art finds some solutions by dealing with the workload distribution problem from three different levels. That is, the solutions are found in methods such as packet level workload distribution, layer level workload distribution, and connection level workload distribution.
According to the packet level distribution method, the loads of the processors at a packet level are monitored and IP packets are distributed across processors accordingly. This method seems to be fine-grained because the granularity of distribution is a single packet. However, this method has been proven to be an audacious proposal and does not work well for connection oriented protocols like TCP (although this technique has been proved to be effective while working with layers like UDP). Anomalies of packet level workload distribution such as out-of-order packet handling can play havoc with network performance and render the packet level workload distribution unreliable.
The layer level distribution method distributes the workload of various layers like IP, TCP, UDP onto various processors. This introduces additional queuing delays and context switches per packet level. Thus, it is also found to be limited in exploiting available parallel processing mechanism. Moreover, this mechanism can not scale to large numbers of processors since there are only a small number of layers.
For the connection level distribution method distributing TCP workload, statically mapping connections to processors can lead to load imbalance, and other negative performance impacts for a specific processor-bound application. The traditional dynamic mapping mechanism is not scalable, since the number of connections can be in the tens of thousands and re-balancing such large numbers of connections cannot be done in a performance-sensitive path like the network protocol path.
The main issue is to ensure that the workload distribution is equitable so that no processor is overloaded or underloaded thereby causing performance bottlenecks or resource waste. On the other side, because the network protocol path is performance sensitive, it is important that the workload balancing mechanism itself is not process intensive or resource intensive which adds itself as a “heavy weight” load to the processors.
Another technical bottleneck in a multiple processor system is a single timer thread structure, in which only one timer thread is designated for all processors. In order to optimize the advantage of having multiple processors in the system, multiple timer threads are desired to be used for parallel processing.
What is needed is an efficient method and system for equitably distributing process workload in a multiple processor network environment and an appropriate mechanism for using multiple timer threads.